INCREASING VOLUME OF BLOOD 103 



0.03 gm., Dextrose 0.1 gm., and Distilled Water enough to make 

 100.0 mils. This solution contains the necessary salts, is alkaline, 

 and nutritive. 



Einger-Locke Solution is the same as Locke's solution without, 

 the dextrose. 



Ringer's Solution adapted especially for laboratory work upon 

 frogs and turtles contains O.Y per cent, of sodium chloride with the 

 chlorides of potash and calcium. 



It is necessary in order to understand the effects of saline solu- 

 tions in the body to know and understand sxich physiologic terms as 

 filtration, diffusion and osmosis and the characteristics of isotonic, 

 hypotonic and hypertonic solutions. This is better discussed in the 

 texts on physiology than can be attempted in this work. Since large 

 amounts of fluid are passed into the blood in infusion, solutions 

 should be as near isotonic with the blood as possible for the follow-: 

 ing reasons : 



If a hypertonic solution is used, i.e., one that contains too much 

 salt, the blood abstracts fluid from the tissues, which still further 

 dilutes it and increases its volume. Furthermore, a strong hyper- 

 tonic solution would injure the blood cells. On the other hand, a 

 hypotonic solution tends to lake the blood. The effects of salines also 

 differ greatly according to whether the volume of the blood has been 

 reduced below normal or not. 



When the Volume of Blood Is Not Decreased. There is so 

 strong a tendency in normal animals for the blood to regain its nor- 

 mal condition that the regulating mechanism starts almost as soon as 

 the infusion is begun. The increased blood pressure causes an in- 

 creased pouring out of weak lymph and this is followed by the 

 elimination of liquid through the intestines and kidneys (Starling), 

 so that according to Crile the volume of blood will return to normal 

 within half an hour and its constituents regain the usual propor- 

 tions. 



On account of the above actions, the addition of saline has only 

 a transitory mild effect upon blood pressure, and chiefly increases 

 urination and tendency to edema. 



Orile found, further, that the dilution of the blood does not 

 prevent the action of circulatory stimulants; and that if vasocon- 

 strictors are administered at the same time as the infusion, the pres- 

 sure could be raised above normal for a time ; but when the splanch- 

 nic arteries were excluded, the dilution of the blood took place so 

 rapidly with the progress of the infusion that edema set in very 

 rapidly although the pressure was not necessarily raised. Hence in 

 intravenous infusions, since the fluid must pass to the right heart 

 and to the lungs first, pulmonary edema is favored; and especially 

 is this the case if at the same time there is a marked back pressure 

 in the left heart from constriction of the peripheral arterioles. 



